Conventional electric tools, especially those including spinning device, generally employ a speed reduction device to provide multiple gearing feature and have different output torques. The speed reduction device includes a planetary gear system including a sun gear, a plurality of planet gears, inner gears and a disk. These gears and disk are arranged to play different roles, such as input or output members, so as to have different output speeds. Nevertheless, complicated assembling and/or manufacturing difficulties are involved in the existing electric tools with multiple gearing switch device such that high price and risk of maintenance are commonly seen, which does not satisfy the users. Besides, only two or three speeds can be chosen because of limitations of the conventional gearing switch device.
Therefore, it is desired to have a gearing switch device that is able to improve one or more problems existing in the conventional gearing switch device.